Field of the Invention
The invention relates in general to a communication device, and more particularly to a control circuit and a control method of a data receiver of a communication device.
Description of the Related Art
Most communication devices demand certain precisions on clocks to ensure that data can be correctly obtained from data signals. Taking Universal Serial Bus (USB) for example, the precision of the frequency of a working clock needs to be within ±500 ppm. On the other hand, in response to the trend of being compact and light of electronic products, many communication devices have adopted in-chip oscillation circuits rather than crystal oscillators that occupy too much space. However, an oscillation circuit is incapable of generating sufficiently precise clocks, and such issue puts communication devices needing precise clocks to a big test. Therefore, there is a need for a control circuit and a control method applied to a crystal-less oscillator communication device, so as to guarantee stable operations of the communication device given a reduced volume.